Bifurcation properties of the two process model

Abstract Daan's two process model is known to be one of the most powerful models, covering various situations from free-running to sleep deprivation. In this study, bifurcation properties of the model dynamics as function of a gap, D , between the threshold processes are clarified using a circle map. As a function of D , we will show that the model has the different types of the mutual entrainment regions that are intervened by the tangent bifurcation. The variable behavior of human circadian rhythm is suggested to be systematically understood based on the bifurcation properties of the two process model.     

Advancing Nursing Practice with a Unit-based Clinical Expert

Objective: To explore patterns in the practice of nursing and patient outcomes.
Design: Qualitative field research.
Population, Sample, Setting: Populations were critical care nurses and critically ill adult patients in the 10-bed medical critical care unit of a 900-bed teaching hospital. A convenience-purposive sample of 27 nurses and 31 patients was studied in 1985.
Methods: Six months of participant observation, unstructured interviews, and the constant comparison method of grounded theory.
Findings: Markedly different patterns were found in expert and nonexpert practice. The substantive theory of conversion helped explain how the majority of nonexpert nurses advanced their practice. The metaphor of catalyzed conversion captures how a unit-based expert nurse serves as a catalyst to advance the practice of nonexperts. Presence, defined as the way of being within a given clinical context, differentiated nurses.
Conclusions: (a) Expert and nonexpert practices are substantively different, (b) Expert and nonexpert practice results in different patient outcomes, (c) Conversion helps explain changes in nonexpert practice.
Clinical Implications: A unit-based expert nurse can increase patient-focused care.     

11项心功能指标的计算方法及微机处理

本文用OMEGA 500型Υ相机和MCS 560计算系统,即SPECT,R波门控采集心血池图象,在此基础上进行曲线分析,编制BASIC程序计算11项心功能指标。临床应用结果表明:PFR、LVFF、FFR是舒张期功能的优选指标,其它指标对心功能评价也都有显著意义。     

基于层次分析评价和模糊综合评价模型的临床医学课程思政实施效果评价

目的 探索基于层次分析评价和模糊综合评价模型的临床医学课程思政实施效果评价体系构建和应用。方法 利用Yaahp软件构建基于层次分析评价和模糊综合评价模型的临床医学课程思政实施效果评价体系。在西安交通大学第一附属医院185名学生的内科学课程中实施德医并举的课程思政清单式教学,并在课程结束时应用此评价体系得到定量的综合评价结果。结果 基于层次分析评价和模糊综合评价模型构建了临床医学课程思政实施效果评价体系,以德医双馨的育人目标为目标层,师德师风、课程设计、学生体会、发展评估为准则层,分13项方案层。利用此评价体系评价2020至2021学年第一学期内科学课程思政实施效果,结果显示德医并举的课程思政清单教学具有良好的育人效果,定量综合评价得分4.080分（1~5分）。结论 临床医学课程思政实施效果的评价可基于层次分析评价和模糊综合评价模型构建,具有科学、定量、综合和可改进等特点。     

Oxygen uptake-heart rate relationship in élite wheelchair racers

The American College of Sports Medicine (ACSM) recommends that, as a general rule for health purposes, individuals should exercise at 40%–85% of their maximal oxygen uptakes. Moreover, it has been suggested that 55%–90% of the maximal heart rate may be used as an alternative estimate of these percentage maximal oxygen uptake values. The present study examined the relationship between percentage peak heart rate (% HR_peak) and percentage peak oxygen uptake (% ) during steady-state incremental intensity wheelchair propulsion of 16 élite, male wheelchair racers (WR). Oxygen uptake was determined during each submaximal exercise stage and heart rate (HR) was continuously monitored. The was subsequently determined using a separate protocol. Linear regression equations of % HR_peak versus % for each participant included % HR_peak values corresponding to 40%, 60%, 80% and 85% . The linear regression equation, derived as the group mean of the slope and intercept terms determined for each individual, was: . The group mean of the individual correlation coefficients for the relationship was 0.99. The values of % HR_peak for each of the % values below 85% were significantly greater (P<0.01) than those suggested by the ACSM. This suggests that the ACSM guidelines below 85% , based on % HR_peak, may underestimate the relative exercise intensity (i.e. % ) in the WR population. However, in élite level WR, % HR_peak can be recommended as an alternative estimate of % at wheelchair propulsion intensities of 85% or more. Electronic Publication     

枢椎齿突骨折的有限元分析

目的：建立枢椎的三维有限元(FE)模型，探讨在前、后方不同载荷下齿突的不同损伤机制和骨折类型。方法：对一例新鲜枢椎标本进行CT扫描，层厚1mm，扫描图像转换后输入微机，通过软件PRO／E重建枢椎的三维立体模型，再转入有限元软件MARK并赋予此模型物理材料属性，然后模拟齿突骨折的受力条件，在齿突中性矢状面对齿突施加不同角度的载荷，分析各种条件下枢椎模型的应力、应变分布，探讨相应条件下可能导致的枢椎齿突骨折类型。结果：(1)对于齿突前部斜向后下方载荷，应力集中区从齿突前上部斜贯穿至后下部；对于齿突前部斜向后上方载荷，应力集中区从齿突前下部斜贯穿至后上部；齿突腰部始终保持高应力；(2)在齿突后部载荷下，其应力集中情况与前部载荷相似，不过应力集中区位置有所偏下。结论：(1)在齿突中性矢状面，齿突前部载荷容易导致齿突腰部发生断裂，形成枢椎齿突Ⅱ型骨折，也可能导致基底部发生断裂，形成枢椎齿突Ⅲ型骨折；(2)齿突后部载荷更容易导致基底部发生断裂，形成枢椎齿突Ⅲ型骨折。     

Sleep in seasonal affective disorder patients in forced desynchrony: an explorative study

The majority of winter-type seasonal affective disorder (SAD) patients complain of hypersomnia and daytime drowsiness. As human sleep is regulated by the interaction of circadian, ultradian and homeostatic processes, sleep disturbances may be caused by either one of these factors. The present study focuses on homeostatic and ultradian aspects of sleep regulation in SAD. Sleep was recorded polysomnographically in seven SAD patients and matched controls subjected to a 120-h forced desynchrony protocol. In time isolation, subjects were exposed to six 20-h days, each comprising a 6.5-h period for sleep. Patients participated while being depressed, while remitted after light therapy and in summer. Controls were studied in winter and in summer. In each condition, the data of each subject were averaged across all recordings. Thus, the influence of the effects of the circadian pacemaker on sleep was excluded mathematically. The comparison of patients with controls and with themselves in the various conditions revealed no abnormalities in homeostatic parameters: sleep stage variables, relative power spectra and time courses of power in various frequency bands across the first three non-rapid eye movement-rapid eye movement (NREM-REM) cycles showed no differences. The data suggest that homeostatic processes are not involved in the disturbance of sleep in SAD.     

益精养血方对帕金森病大鼠多巴胺能神经元Caspase-3表达的影响

目的研究益精养血方对帕金森病(Parkinson's disease,PD)大鼠多巴胺能神经元Caspase-3表达的影响。方法将微量6-羟多巴胺(6-OHDA)立体定向注射于SD大鼠中脑右侧黑质以建立大鼠帕金森病模型,将造模成功的实验动物随机分为模型组、实验(中药)组,每组6只;另纳入6只正常大鼠为正常组。正常组和模型组大鼠生理盐水灌胃,实验组大鼠益精养血方灌胃,各30天。灌胃结束两周后进行行为学检测,免疫组织化学方法观测黑质酪氨酸羟化酶(TH)、Caspase-3的表达。结果实验组大鼠的旋转圈数比治疗前明显减少(P<0.05),实验组损毁侧与健侧黑质TH阳性细胞数量百分比较模型组显著提高(P<0.05),实验组损毁侧黑质Caspase-3表达的OD值比模型组显著降低(P<0.05)。结论益精养血方可使帕金森病大鼠多巴胺能神经元Caspase-3的表达降低,明显抑制神经细胞凋亡。